Unusual Eroding of Anitfoul

[goneyachting]

I have some unusual eroding of my antifouling (Seajet Shogun) around an anode, the anode seems not to be corroding as much as usual, has anyone seen this before and can offer a reason why it might be happening?

[Pete7]

Could it be the anode isn't connected as well as last year or an internal bonding wire has corroded? Been there and only found it when I moved the wire out of the way and it snapped off

Seajet has a good reputation this side of the pond and we may well be using it next year in place of Internationals Uno, which whilst okay isn't brilliant.

Pete

[GordMay]

Greetings and welcome aboard the CF, goneyachting.

I’ll second Pete’s hypotheses.

[goneyachting]

Nothing wrong with the wiring and tested OK with a multimeter. I am wondering if the anode's rubber backing is the problem and the anode is in direct contact with the hull??

[Pete7]

Originally Posted by goneyachting

Nothing wrong with the wiring and tested OK with a multimeter. I am wondering if the anode's rubber backing is the problem and the anode is in direct contact with the hull??

You are going to tell us its a steel hull next, yes?

Pete

[ShipShape]

It is possible that this is the "halo effect" caused your anode reacting with the copper in the antifouling paint. There were some bad zincs from China recently, you may have one of them.

If your anode has a rubber backing how is it connected to the bonding system?

[barnakiel]

Zink vs. copper.

b.

[fstbttms]

Originally Posted by ShipShape

It is possible that this is the "halo effect" caused your anode reacting with the copper in the antifouling paint. There were some bad zincs from China recently, you may have one of them.

This "halo effect" is relatively common, has been happening for many years and has nothing to do with the quality of the zincs or where they were produced.

Originally Posted by ShipShape

If your anode has a rubber backing how is it connected to the bonding system?

I suspect the OP is referring to a ZHC-2 zinc, which is a small, 2-hole plate zinc that mounts on studs protruding from the hull. These sometimes have a rubber backing mat that isolates the zinc from contact with anything but the mounting hardware.